1. Field of the Invention
The invention is as described herein and shown in the accompanying drawings is for a rail welding apparatus incorporating a railroad rail restraining device, weld containment device and weld delivery unit having improved rail restraining characteristics, improved weld supporting properties and being compact, lightweight and economical for greater utility. The restraining device enables the positioning of rail ends of either long prewelded rails, special rail sections for appliances such as in frogs or turn-outs or switches, existing rails in need of repair, or a combination of these. Because of the high strength, improved geometry and design, the device can be utilized in the gas-arc welding of highly restricted clearance rail splices or joints, such as in welding a length of rail to a turn-out assembly.
2. Description of Related Art
In the prior art, there are three main ways to weld railroad track. These include aluminothermic welding (U.S. Pat. Nos. 5,215,139 and 5,306,361), flash-butt welding (U.S. Pat. Nos. 4,929,816; 5,270,514; and 5,469,791); and gas-arc welding (U.S. Pat. No. 5,605,283). These all have certain advantages and disadvantages. Aluminothermic welding has low equipment requirements, is economical to perform but produces welds of less strength than the other methods. Flash butt welding uses complex equipment but produces high strength welds, however it is difficult to use to join rails in the field, and results in a loss of rail length, which can cause difficulties. Gas-arc welding requires precise alignment and a considerable length of time to perform a weld of sufficient strength, heretofore also requiring equipment of considerable size, complexity and cost. The invention enables the use of gas-arc welding with greater ease and lower cost.
The rail restraining device, weld containment device and weld delivery unit of the invention needs to handle rail sections often as long as one-quarter mile, aligning rail ends precisely for welding, yet can be made sufficiently compact to be incorporated on a hi-rail equipped over-the-road truck or shipping container on a chassis or car having economy and requiring no special licensing or equipment for over-the-road use while being sufficiently small sized itself to fit in the space available to weld rails even to switch or turnouts or in frogs where the weld joint is separated from the adjacent rail portion by as little as about 7xe2x80x3 to 11xe2x80x3.
The rail restraining device and weld delivery unit takes up a sufficiently small volume of space that the truck can be fitted with room for the welder itself, control devices; generator; and gas bottles; as well as the welding robot mounted on the unit.